VLC Media Player - VLC is a free and open source cross-platform multimedia player and framework.
BitTorrent - BitTorrent is a peer-to-peer program developed by Bram Cohen and BitTorrent, Inc.
foobar2000 - An advanced freeware audio player for the Windows platform.
Soulseek - Soulseek® is a unique ad-free, spyware free, and just plain free file sharing application.
Winamp - Winamp is a media player that allows users to play multiple-file formats, arrange media in a varied file-management system, and play unique media with AAC encoding.
Shareaza - Shareaza is the most luxurious and sophisticated file sharing system you'll find.